Using a UISegmentedControl to change UIPickerView Labels

Question

I've attempted to implement a UISegmentedControl in order to use a switch statement for deciding which array should populate a UIPickerView, however this approach which is written in swift hasn't worked as expected. Has anyone else explored this problem before or may have any ideas to how these functions could work together?

Here is the code so far:

    import UIKit


class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {

    var rejuvenatedEnterprisesEmployees = [
        Employees(name: "Jeffrey Wells", employeeRoles: ["Accountant", "Designer"], departmentID: 0),
        Employees(name: "Victor Atkins", employeeRoles: ["Director of IT", "Sales Stategist"], departmentID: 0),
        Employees(name: "Kelli Hamilton", employeeRoles: ["Director of Sales"], departmentID: 0),
        Employees(name: "Adam Braun", employeeRoles: ["Sales Lead"], departmentID: 1),
        Employees(name: "Brian Cruz", employeeRoles: ["Designer"], departmentID: 1),
        Employees(name: "Kristen Floyd", employeeRoles: ["Developer"], departmentID: 1),
        Employees(name: "Lois Martinez", employeeRoles: ["Curator", "Blogger"], departmentID: 2),
        Employees(name: "Michael Lind", employeeRoles: ["Sales, Administrator"], departmentID: 2),
        Employees(name: "Eric Bay", employeeRoles: ["Database Admin"], departmentID: 2),
        Employees(name: "Brandon Young", employeeRoles: ["Artist"], departmentID: 2)
    ]
    var rejuvenatedEnterprisesVictorsEmployees = [
        Employees(name: "Victor Atkins", employeeRoles: ["Director of IT", "Sales Stategist"], departmentID: 0),
        Employees(name: "Adam Braun", employeeRoles: ["Sales Lead"], departmentID: 1),
        Employees(name: "Brian Cruz", employeeRoles: ["Designer"], departmentID: 1),
        Employees(name: "Kristen Floyd", employeeRoles: ["Developer"], departmentID: 1)
    ]
    var rejuvenatedEnterprisesKellisEmployees = [
        Employees(name: "Kelli Hamilton", employeeRoles: ["Director of Sales"], departmentID: 0),
        Employees(name: "Lois Martinez", employeeRoles: ["Curator", "Blogger"], departmentID: 2),
        Employees(name: "Michael Lind", employeeRoles: ["Sales, Administrator"], departmentID: 2),
        Employees(name: "Eric Bay", employeeRoles: ["Database Admin"], departmentID: 2),
        Employees(name: "Brandon Young", employeeRoles: ["Artist"], departmentID: 2)
    ]
    var squaredEnterprisesEmployees: [String] = ["Jeffrey Wells","Victor Atkins","Kelli Hamilton","Adam Braun","Brian Cruz","Kristen Floyd","Lois Martinez","Michael Lind","Eric Bay","Brandon Young"]

    //UIPicker Scroll component
    let kManagerScrollComponentCount: Int = 1
    let kManagerScrollComponent: Int = 0
    //UIPicker Scroll component

    var chosenManagerScrollView: UILabel = UILabel(frame: CGRectMake(40,0,170,72))

    @IBOutlet weak var employeeListing: UITextView!
    @IBOutlet weak var userTicketLocation: UILabel!
    @IBAction func addEmployee(sender: AnyObject) {


    }

    @IBOutlet weak var segmentedControl: UISegmentedControl!
    @IBAction func indexChanged(sender: UISegmentedControl) {
        switch segmentedControl.selectedSegmentIndex
        {
        case 0:
            func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView?) ->UIView {
                //var chosenManagerScrollView: UILabel = UILabel(frame: CGRectMake(40,0,170,72))
                chosenManagerScrollView.backgroundColor = UIColor.clearColor()
                var jumperCables: [String] = []
                for var i = 0; i < rejuvenatedEnterprisesEmployees.count ; ++i {
                    jumperCables.append(rejuvenatedEnterprisesEmployees[i].name)
                }
                chosenManagerScrollView.text = jumperCables[row]
                return chosenManagerScrollView
            }
        case 1:
            func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView?) ->UIView {
                //var chosenManagerScrollView: UILabel = UILabel(frame: CGRectMake(40,0,170,72))
                chosenManagerScrollView.backgroundColor = UIColor.greenColor()
                var jumperCablez: [String] = []
                for var i = 0; i < rejuvenatedEnterprisesVictorsEmployees.count ; ++i {
                    jumperCablez.append(rejuvenatedEnterprisesVictorsEmployees[i].name)
                }
                chosenManagerScrollView.text = jumperCablez[row]
                return chosenManagerScrollView
            }
        default:
            break; 
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
        return kManagerScrollComponentCount
    }

    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return rejuvenatedEnterprisesEmployees.count
    }


    func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView?) ->UIView {

        switch segmentedControl.selectedSegmentIndex
        {
        case 0:
                let chosenManagerScrollView: UILabel = UILabel(frame: CGRectMake(40,0,170,72))
                chosenManagerScrollView.backgroundColor = UIColor.clearColor()
                var jumperCables: [String] = []
                for var i = 0; i < rejuvenatedEnterprisesEmployees.count ; ++i {
                    jumperCables.append(rejuvenatedEnterprisesEmployees[i].name)
                }
                chosenManagerScrollView.text = jumperCables[row]
                return chosenManagerScrollView
        case 1:
                let chosenManagerScrollView: UILabel = UILabel(frame: CGRectMake(40,0,170,72))
                chosenManagerScrollView.backgroundColor = UIColor.greenColor()
                var jumperCablez: [String] = []
                for var i = 0; i < rejuvenatedEnterprisesVictorsEmployees.count ; ++i {
                    jumperCablez.append(rejuvenatedEnterprisesVictorsEmployees[i].name)
                }
                chosenManagerScrollView.text = jumperCablez[row]
                return chosenManagerScrollView
        default:
            print("done")
            let chosenManagerScrollView: UILabel = UILabel(frame: CGRectMake(40,0,170,72))
            chosenManagerScrollView.backgroundColor = UIColor.clearColor()
            var jumperCables: [String] = []
            for var i = 0; i < rejuvenatedEnterprisesEmployees.count ; ++i {
                jumperCables.append(rejuvenatedEnterprisesEmployees[i].name)
            }
            chosenManagerScrollView.text = jumperCables[row]
            return chosenManagerScrollView

        }
    }



    func displayEmployeeGroup(chosenEmployee: String, fromComponent chosenComponent: String) {

        switch chosenEmployee {
            case chosenEmployee where chosenEmployee == "Jeffrey Wells":
                for employee in rejuvenatedEnterprisesEmployees {
                    print(employee)
                    employeeListing.text = "\(employee)\n"
            }
            case chosenEmployee where chosenEmployee == "Victor Atkins":
            break

            case chosenEmployee where chosenEmployee == "Kelli Hamilton":
            break

        default: print("done")
        }
        if chosenEmployee == "Jeffrey Wells" {
            for employee in rejuvenatedEnterprisesEmployees {
                print(employee)
                employeeListing.text = "\(employee)\n"
            }
        }
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        let chosenEmployee: Int = pickerView.selectedRowInComponent(kManagerScrollComponent)
        displayEmployeeGroup(squaredEnterprisesEmployees[chosenEmployee], fromComponent: "the list of employees")
    }




    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

Answer 1

You haven't understood how data source / delegate messaging works. This code doesn't do what you think it does:

case 0:
    func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView?) ->UIView {

That won't magically cause this function to be the data source viewForRow method. It merely defines a local function which comes into existence and vanishes again instantly, to no point. You must implement viewForRow at the top level of your view controller like all your other methods. It must make the choice based on the segment selected. (In fact I think you've already set that up.) The segmented control, when its value changes, then merely tells the picker view to reload (eg reloadAllComponents ) and thus cause viewForRow to be called again.